<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>


<script>

    var myWorker = new Worker("worker_demo.js");

    myWorker.postMessage(100)

    myWorker.onmessage = function (event) {
        console.log("Called back by the worker!\n");
    }

</script>
</body>
</html>